1. Field of the Invention
The disclosed invention relates to computer network protocol gateways, and more specifically, to gateways adapted to power line networking systems.
2. Description of the Related Art
The widespread availability of computers, especially personal computers, has generated a rapid increase in the number of computer networks. Networking two or more computers together allows the computers to share information, file resources, printers, etc. Connecting two or more personal computers and printers together to form a network is, in principle, a simple task. The computers and printers are simply connected together using a cable, and the necessary software is installed onto the computers. In network terminology, the cable is the network medium and the computers and printers are the network nodes. The network nodes “talk” to one another using one or more protocols such as Transmission Control Protocol, Internet Protocol (TCP/IP).
Gateways are used to perform protocol translations from one protocol to another protocol, so that two networks that use different protocols can be interconnected. For example, the Prodigy network service has a gateway that translates between its internal proprietary e-mail format and the Internet e-mail format.
Standard network protocols are typically designed under the assumption that each network node is a “smart” device having substantial processing and storage capabilities. For example, a typical Personal Computer (PC) has more than enough processing and storage capability to handle almost any network protocol. However, a typical printer is a “dumb” device that does not have the necessary processing and storage capabilities. Some manufacturers provide network printer adapters that allow a printer to be connected to a network. The printer adapters are single board computers that provide processing and storage capabilities similar to that of a fully configured PC. The network printer adapter thus converts the “dumb” printer into a “smart” device. Although the network printer adapters do work, they are relatively expensive and therefore unsuitable for many home and small office environments. Moreover, the printer adapters are not well suited for connecting other non-PC devices to a network. For example, users often desire to connect dumb devices such as outdoor lights, alarm systems, telephone systems and the like, to their computer networks. Buying a network adapter card to turn each of these dumb devices into a smart device would be prohibitively expensive.
The protocols used for smart devices are usually called “network protocols”. The protocols used for dumb devices are often called “control protocols.” The network protocols are quite different from the control protocols, both in capabilities and in complexity. Because of these differences, gateways designed to transfer data between network protocols are typically ill-suited to the task of transferring data between control protocols. Even more difficult is the task of transferring data between a network protocol and a control protocol.
Existing home control/automation products have tended to use control protocols that are based on a peer-to-peer model rather than a centralized client/server model. This severely limits the usability of these products, as each node is required to store state information and rules locally. Configuration of the network is often difficult due to a lack of easy-to-use, centralized user interface components. Furthermore, interoperability between competing products (X-10 and CEBus for example) has been virtually impossible.